This depends on your operating system. I have done this using Applescript on Macs before. Once any edits are done the image needs to be dropped back into the container. You basically export the file and open it in the other application.
Here is one I used for iPhoto edits of products (export a set of product photos from FM and send all product photos to an album named for the SKU of the product or create a new album if it does not exist already):
"set theFolder to " & Quote ( $path );
"set albumName to " & Quote ( $SKU );
"tell application " & Quote ( "iPhoto" ) & " to if not (exists album albumName) then new album name albumName";
"tell application " & Quote ( "iPhoto" );
"import from alias " & Quote ( $path ) & " to album albumName";
"tell application " & Quote ( "Finder" );
"delete files of folder theFolder";
Something similar could be used for Photoshop. This is only the Applescript part and there is obviously more to the whole process but this might be what you are looking for. I think you could add some sort of macro to run Applescript to send the image back to the container but that might be more complicated of a task. drag and drop at that point is not a big deal.
I believe there is a way to do this in Windows, but I do not know how that works.
There are some FM plugins that allow some basic editing, but nothing full featured like Photoshop.
Hi and thanks for the reply,
I am using a mac so things should work the same as in your example. I will give it a go when I can find the time.